Numerous types of key-in-knob/handle lock arrangements have been developed. Generally all such arrangements are characterized by having a latch bolt operable by an outside door handle or cylinder. A lock mechanism of such systems can be set in a manner preventing rotation of the outer knob or handle to retract the latch bolt. Typically, the outer knob or handle is mounted upon a spindle arrangement. The lock spindle or spindle arrangement provides for translation of the rotational motion of the outside knob to operation of the latch bolt mechanism. The lock mechanism is typically used to prevent rotation of the spindle and the outer knob.
In many conventional systems an inner doorknob of the arrangement includes a centrally positioned button or knob thereon which can be selectively set in a position causing prevention of rotation of the outer knob and spindle. In such systems, the outer knob may include a lock cylinder therein which, when operated by a key, translates motion into the internal hardware, to free the spindle for rotation and/or retract the latch bolt. Generally, the key-in-knob/handle lock set hardware, internally, includes a driver engaged by an extension of the lock cylinder. As the lock cylinder is rotated, the driver or driver mechanism is engaged and rotated, unlocking the door or retracting the latch bolt. In those systems which utilize a button on the inside knob for locking, rotation of the driver generally generates a dislodging of the locking button from its locked position.
A wide variety of types of lock cylinders or cylinder arrangements have been utilized in key-in-knob/handle locksets. In many instances a preferred cylinder is one which can be readily removed and replaced. Generally such cylinders are termed interchangeable core cylinders and many include a projection thereon which is oriented to engage a receiving space within the knob, to retain the cylinder in position. The extension is selectively extendable and retractable, to be received within the knob receiving space. Operation of the extension is generally conducted by means of a control key that can be inserted in a cylinder arrangement to operate the extension, without operating the lock mechanism.
In other systems, the lock cylinder is not readily removable and replaceable, by means of a control key. Rather, for such systems substantial disassembly of the lock, often including disassembly of the internal lock hardware, may be necessary for removal and replacement of the cylinder itself.
Key-in-knob/handle lock sets, including conventional doorknob systems, are used in a variety of applications including office buildings, college or university campuses, airports, hospitals, schools, apartment complexes, museums and in similar institutions. Very often in such facilities many or all of the key-in-knob/handle lock sets are keyed to a single master key. That is, a single master key can be used to obtain passage through any door on that master key system. Such systems are well known and very convenient.
For security reasons it is often desireable to change all of the lock cylinders in a master key system. This may be done, for example, to prevent loss of security as keys are lost or as employees leave with keys or copies of keys. Also, it may be desireable to re-key systems periodically just as a precaution or to update a system. In most key-in-knob/handle lock sets this is possible, however in some it is more easily accomplished than in others. In systems having interchangeable core locks operable by a master key, changing lock sets can be relatively easy, provided the lock cylinder is changed to one appropriately designed for engaging the existing lock and knob. This, generally, has required replacement with a lock cylinder of the same or similar manufacture as the one originally removed.
In other systems, changing lock cylinders is considerably more difficult. For example, substantial disassembly of the hardware may be necessary, which leads to a substantial cost and usually requires the services of a locksmith. Further, in the past the lock cylinder for such arrangements had to be replaced with a cylinder of the same or similar manufacture.
In general, in the past it has not been readily possible to convert a key-in-knob/handle lock set from one manufacture or style of lock cylinder, to another. This has been generally true regardless of the manufacture and nature of the key-in-knob/handle lock set. In arrangements having interchangeable core locks, since interchangeable core locks of various manufacturers are not made to universal standards one lock core generally could not be readily replaced with one of another's manufacture. For systems without interchangeable core locks, the problem has been analogous.
At least one system has been proposed for conversions. This system involves the production of a special adaptor knob to replace the outer knob of a particular model or design of doorknob. The adaptor knob includes means for receiving an interchangeable core, different from that in the original knob. An adaptor is provided to permit mechanical communication between the new knob and the old hardware. The system is impractical, in part, because each design of lock set requires a specially designed custom replacement knob, thus making conversion impractical unless done on a very large scale.
In the past, impractical convertability has posed substantial problems. For example, if an office building or institution is fitted with dozens, or perhaps hundreds, of lock sets without readily interchangeable cores, obtaining interchangeable cores or improvement in lock cylinder quality has been an expensive proposition. This generally results since conversion often requires disassembly of each and every lock set and in many instances a complete replacement of the hardware.
Even in lock systems with interchangeable cores there have been problems. For example, if the manufacturer of a particular design of interchangeable core cylinder goes out of business, there may not be a ready source of replacement cores. Further, an improvement in lock core quality, by means of obtaining a different core of different design from a different manufacturer, is not readily available since it would not fit the existing knob. Again, manufacturing a custom knob or handle for each and every design of lock set is an expensive process.
What has been needed has been a method and apparatus system for converting a lock set to an arrangement having a universal key-in-knob/handle. For systems that do not have interchangeable cores, this can be used to achieve desired interchangeability. By "universal knob/handle" it is meant that the knob/handle is such that it can be mounted on substantially any lock set. The universal knob/handle would be, however, typically designed for the mounting of only one style or design of lock cylinder therein. To convert cylinder type the universal knob is such that it can be removed and replaced by a different universal knob appropriately adapted for receipt of a lock cylinder of a different manufacture or design. Thus, what has been needed and is provided is a system of universal knobs each of which is appropriately adapted for mounting on a variety of hardware systems, and each of which is appropriate for receipt of a particular style, design or manufacture of lock cylinder. As a result of this system, substantially any key-in-knob/handle hardware set of any manufacturer could be efficiently converted to an arrangement utilizing a lock cylinder of any manufacture.